Been a while since I've updated this due to an unexpected health problem that laid me up for a month.
Engine testing is progressing, initially I've been concentrating on getting exhaust gas temps (EGT) down to reasonable levels. The first couple of runs EGTs were around 720 degrees C which is at least 100 degrees too high. The cause was traced to case leaks and a rubbing compressor wheel both of which have been addressed.
Testing methodology has been to run the engine at a set speed starting at 35k rpm, burn a full tank of fuel ( 500ml ), shutdown and inspect critical parts, increase speed by 5K rpm and repeat the entire test. Maximum speed attained so far is 50K rpm.
Here's a video clip of the test at 45K rpm.
[ame]http://youtu.be/fUZqlS1nt_w[/ame]
The start was a bit hot as the starter, a dremel, was removed too early forcing the turbine to work harder than necessary to get up to speed, plus I was a bit heavy handed on the fuel control.
Another ( very blurry ) clip showing the arduino displaying RPM and EGT for the 50K run. The temps displayed here are about where they should be, so I'm pleased with progress so far.
Thanks for reading.
Steve.